1. Field of the Invention
The present invention relates to a three-dimensional display able to display the image of a three-dimensional object while giving a three-dimensional sensation.
2. Description of the Related Art
FIG. 30 is a general block diagram of an example of a three-dimensional display of the related art.
This three-dimensional display enables images of an object 100 taken from three different perspectives, that is, by the cameras 111 to 113, to be viewed at viewing perspectives P1 to P3 corresponding to the cameras 111 to 113 so as to give the user a three-dimensional visual sensation.
That is, an object 100 with a sectional shape including a white front face 101, a blue side face 102, and a red side face 103 is captured by different perspective cameras 111 to 113. The captured images S1 to S3 are sent to a high speed CRT 120.
At this time, the image S1 of the object 100 taken by the camera 111 is displayed in the form as shown in FIG. 31, the image S2 of the object 100 obtained by the camera 112 is displayed in the form as shown in FIG. 32, and the image S3 of the object 100 obtained by the camera 113 is displayed in the form as shown in FIG. 33.
These images S1 to S3, as shown in FIG. 30, are successively sent to the CRT 120 and displayed at a predetermined timing at the CRT 120.
This being so, a shutter device 130 operates at the timing of display of the images S1 to S3 and changes the path of the light emitted from the CRT 120 at the time of display of the images S1 to S3.
Specifically, the light at the time of display of the image S1 is refracted at the shutter device 130 as shown by the solid line, the light at the time of display of the image S2 passes out from the shutter device 130 as shown by the two-dot chain line, and the light at the time of display of the image S3 is refracted at the shutter device 130 as shown by the one-dot chain line.
A Fresnel lens 140 arranged behind the shutter device 130 is used to focus the light passing through the shutter device 130 at the viewing perspectives P1 to P3 corresponding to the cameras 111 to 113.
That is, the image S1 taken by the camera 111, the image S2 taken by the camera 112, and the image S3 taken by the camera 113 are displayed on the CRT 120 by time division and are shown to the viewing perspectives P1 to P3 corresponding to the positions of arrangement of the cameras 111 to 113 at the timings of the time division, so the user, due to the change in the viewing perspectives, gets the sensation of viewing the object displayed on the CRT 120 from angles corresponding to those viewing perspectives and thereby obtains a three-dimensional sensation.
There are however the following problems with a three-dimensional display according to the above related art.
In the three-dimensional display of the related art, it is necessary to display the images S1 to S3 obtained by the cameras 111 to 113 on the CRT 120 by time division. The system for doing this is complicated.
Further, if the refresh time is long at the time of switching the images S1 to S3 at the CRT 120, an after image is causedxe2x80x94making the system unusable. Therefore, an expensive CRT 120 able to refresh images in a short time becomes necessary.
Further, a shutter device 130 comprised of an optical lens or liquid crystal shutter and a Fresnel lens 140 becomes essential, so not only does the hardware itself become large in size, but the price also ends up becoming high.
The present invention was made to solve the above problems and its object is to provide a three-dimensional display designed to simplify the display system and reduce the cost of the hardware by enabling viewing of a three-dimensional image by just providing a predetermined mask unit in front of the CRT or other display unit displaying the image.
To achieve the above object, according to an aspect of the invention, there is provided a three-dimensional display comprising a synthesis unit for fetching a plurality of types of images capturing an object from a plurality of different perspectives and combining the plurality of types of images so that one image shifts with respect to an image of a reference perspective corresponding to the distance between the reference perspective and the perspective of that one image and in the direction thereof and thereby generating a single synthesized image, a display unit including a display screen having a number of pixels of at least the number of pixels of the single synthesized image generated at the synthesis unit for displaying the synthesized image on the display screen, and a mask unit comprised of a thin sheet member placed in front of the display screen of the display unit and having a plurality of holes formed at predetermined intervals at locations facing the pixels of the display screen.
Due to this configuration, the synthesis unit fetches the plurality of types of images capturing an object from a plurality of different perspectives and combines the plurality of types of images so that one image shifts with respect to the image of the reference perspective corresponding to the distance between the reference perspective and the perspective of that one image and the direction thereof and thereby generates a single synthesized image. Further, the display unit displays this single synthesized image on the display screen. As a result, a plurality of light beams from the images included in the single synthesized image pass through the holes of the mask unit and focus at locations in accordance with the perspectives of the images. Therefore, the user can view images similar to those seen when looking at an object from different perspectives by moving the viewing perspective to different focusing locations.
According to an embodiment of the invention, there is provided a three-dimensional display, wherein the shape holes of the mask unit are circular or polygonal holes. In particular, the diameter of the circular or polygonal holes is preferably substantially equal to the diameter of the pixels of the display screen. Further, as another example, according to an embodiment of the invention, the plurality of holes of the mask are slit-shaped elongated holes. In particular, the width of the slit-shaped elongated holes is preferably substantially equal to the diameter of the pixels of the display screen.
Further, as an example of the specific configuration of the synthesis unit, according to an embodiment of the invention, there is provided a three-dimensional display, wherein the synthesis unit is comprised of a zoom unit for enlarging or reducing the plurality of types of images to generate zoom images, a shift unit for shifting a zoom image based on a zoom image corresponding to the image of the reference perspective, and a mapping unit for mapping the reference zoom image and the shifted zoom image in that state in a table having substantially the same pixel configuration as the pixel configuration of the display screen to thereby form the above single synthesized image.
It is, however, preferable to remove the unnecessary pixels which should not be viewed from the holes of the mask unit from among the pixels of the synthesized image and then display the image on the display screen. Therefore, according to an embodiment of the invention, there is provided a three-dimensional display, wherein the synthesis unit is provided with a filter unit for comparing (when displaying on the display screen pixels of an image capturing the object from one of the perspectives and included in the single synthesized image) an angle of incidence of light from those pixels to the holes of the mask unit closest to those pixels and a visual angle when capturing a portion of the object shown by those pixels from that perspective and, when these angles are not equal, removing those pixel from the single synthesized image.
Further, when there are few images making up the synthesized image, it is preferable that the viewed image change substantially continuously when the user changes its viewing perspective. Therefore, according to an embodiment of the invention, there is provided a three-dimensional display, further comprising a correction unit for mapping at least one image the same as one image between adjoining images in the single synthesized image.
Further, according to an embodiment of the invention, there is provided a three-dimensional display, preventing contact between an area including a group of pixels of the display screen centered on a single hole and having an angle of incidence of light from outermost peripheral pixels to the single hole substantially equal to the maximum visual angle of the perspective and an area including a group of pixels of the display screen centered on another hole by setting an interval between the single hole and the other hole and providing a condenser lens of a size including even the outside pixels of the area for each area.
Due to this configuration, due to the Fresnel lens, not only the light from the pixels inside the above area, but also the light from pixels outside the area pass through the holes and are viewed by the user.